Influence of the stress gradient at the notch on the critical distance and life prediction in HCF and VHCF

The stress gradient associated with the notch geometry was integrated into the critical distance estimate procedure and formed the Stress Gradient Method (SGM) proposed in this study. The critical distance was discovered to be highly related to the product of the fatigue life and the stress gradient. The fatigue life of varied notched specimens was then pr edicted using SGM and three other typical critical distance determination methods. The results showed that using the SGM was beneficial for enhancing the prediction accuracy of the theory of critical distance (TCD) in the HCF regime. Furthermore, it is acceptable for applying the SGM in the VHCF regime with mean stress.